Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is concerned with a pivot
construction for use in a motor vehicle suspension. This
application is a division of copending Canadian application
Serial No. 281,562 filed June 28, 1977.
In accordance with the present invention, there
is provided a pivot means for a suspension system for
a motor vehicle having a frame member, a wheel support
member constructed to rotatably support a road wheel and
a leaf spring interconnecting said frame member and said
10 wheel support member; the pivot means being connected
to the leaf spring and the frame members; a pair of spaced
apart supports connected to the frame member; the leaf
spring having an eye formed at one end and the eye being
d~$~sed between the supports; a pair of ball studs having
shank portions disposed in the eye; the ball studs having
a pair of spaced apart head portions; each of the head
portions being rotatably supported in a socket means;
the socket means being secured to the spaced apart supports;
and an annular thrust washer and seal surrounding the
shank portions of each of the ball studs; the thrust washer
and seals having elastomeric sealing surfaces engaging
the shank portions of the ball studs; the thrust washer
and seals each having a hat-shape metal core and an elas-
tomeric coating over substantial portions of the exterior
surface of the core; the thrust washer and seals each
having an elastomeric portion engaging the shank portion
of one of the ball studs; whereby the leaf spring may
deflect about a pivot axis that extends through the pair
of spaced apart head portions and is fixed relative to
the head portions and the socket means.
The pre.sent invention also provides a suspension
system incorporating the pivot means. Accordingly, the
present invention also provides a suspension system for a
motor vehicle having a frame member, a wheel support member
35 constructed to rotatably support a road wheel and a leaf
spring interconnecting the frame member and the wheel support
member; pivot means connected to the leaf spring and to the
,7 frame member; a pair of spaced apart supports connected to the
~; ~ frame member; the leaf spring having an eye formed at one end
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and the eye being disposed between the supports; a pair of
ball studs each having a shank portion and a head portion; the
shank portions being arranged in axial alignment with the ends
of the shank portions being in juxtaposed relationship; a
5 sleeve surrounding the shank portions and supported within the
eye; the ball studs having a pair of spaced apart head
portions; each of the head portions being rotatably supported
in a socket means; the socket means being secured to the
spaced apart supports; one of the socket means comprising a
10 plastic bearing disposed in a socket part; an annular retaining
ring disposed in the socket part and engaging the end of the
bearing; the socket part having a peripheral lip engaging the
retaining ring and exerting a preload on the bearing; a first
annular seal having a portion engaging the peripheral lip of
lS the socket part, the retaining ring and the shank portion of
the most adjacent ball stud; an annular thrust washer and
seal having a hat-shape metal core and an elastomeric coating
over substantial portions of the exterior surface of the core;
the thrust washer and seal sealingly engaging the shank portion
20 of the most adjacent ball stud and the sleeve; whereby the
leaf spring may deflect about a pivot axis that extends through
the pair of spaced apart head portions and is fixed relative
to the head portions and the socket means.
The double ball and socket joint construction of this
25 suspension pivot automatically compensates for minor misalign-
ment that may occur between the leaf spring and the frame
bracket. Further, the ball and socket construction offers
minimum frictional resistance to angular displacement of the
spring with respect to the frame bracket. In addition, the
30 seal arrangement assures long bearing life and the pivot means
is suitable for heavy duty truck applications.
The invention is described further, by way of
illustration, with reference to the accompanying drawings, in
which:
Figure 1 is a perspective view of a motor vehicle
suspension having a pivot construction embodying this invention;
Figure 2 is a sectional view taken along section
line 2-2 of Figure l;
Figure 3 is an enlarged sectional view of a portion
40 of the construction of Figure 2; and
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Figure 4 is a sectional view of the con~ination
thrust washer and seal used in the suspension pivot of Figure
2.
Referring now to the drawings, wherein the presently
5 preferred embodiment of this invention is illustrated, Figure
1 discloses a motor vehicle suspension having a novel pivot
construction. In the suspension of Figure 1, a vehicle frame
10 is resiliently supported on a front axle 12 by leaf spring
assembly 14. The rearward end of the leaf spring is connected
10 to the frame member 10 by means of a spring shackle 16. The
forward end of the leaf spring 14 is connected to a frame
bracket 18 by means of a suspension pivot construction that is
shown in detail in Figure 2.
The leaf spring 14 has its forward end formed with a
15 spring eye 16. A sleeve 19 is fitted within the spring eye 16
and has its ends spaced from the ends of the eye. The frame
bracket 18 is provided with bifurcations 20 and 22 that are
pivotally connected to the spring eye 16 by means of left and
right ball and socket joint assemblïes 24 and 26. These
20 assemblies are of identical construction.
The left ball joint 24 includes a polyethylene
bearing 28 of generally cup-shape construction which encloses
the ball portion 30 of a ball stud 32. The plastic bearing 28
is retained within a socket part 34 by means of a retaining
25 ring 36 and the spun-over edge 38 of the socket 34. The spun-
over edge 38 exerts a load on the retaining ring 36 that pre-
loads the bearing 28.
The socket part 34 is situated within a hole 40
formed in the bracket bifurcation 20 and is located therein by
30 a radial flange 42 that is seated against the outside face of
the bifurcation. The bifurcation 20 has a slot 44 that extends
radially frGm the edge of the hole 40. The socket part 34 is
secured in the hole 40 by means of a pinch bolt 46.
The ball stud 32 of the joint 24 has a shank portion
35 47 that extends into the interior of the sleeve 19. An annular
rubber seal 48 engages the end of the socket 34 and sealingly
engages the retaining ring 36 and the shank 47 of the ball stud
32.
A combination thrust washer and seal member 50 has a
40 generally hat-shape construction positioned at the end of the
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spring eye 16. As seen in Figure 3, the member 50 is of
composite construction with a metal backing piece that supports
a rubber piece. A rubber portion 52 of the member 50 is dis-
posed within the eye 16 and sealingly engages the interior of
5 the eye and the shank 47 of the ball stud 32. The rubber
portion 52 also sealingly engages the end of the sleeve 19. A
rubber coating 54 on the member 50 sealingly engages the
adjacent face of the bifurcation 20 of the bracket 18 as well
as the seal 48 and a portion of the shank 47.
The ball and socket joint 26 is constructed in a
manner similar to that of the joint 24. It includes a plastic
cup-shape bearing 60 that encloses a ball 62 of a ball stud 63.
The stud 63 has a shank portion 64 that is fitted within the
sleeve 19. The bearing 60 is situated within a socket 66
15 which, in turn, is retained within a hole in the bifurcation
22 by means of a pinch bolt 68. A pair of seals, similar to
seals 48 and 50, protect the components of the joint 26.
The socket part 66 includes a radially extending
- flange 69 that is constructed to receive a tool. This
20 arrangement permits the socket 66, and thus the ball joint
assembly 26, to be withdrawn from the hole in the bifurcation
22, after the pinch bolt 68 is removed. The socket 34 of the
joint 24 is similarly equipped with a tool receiving flange 70.
The ball joint assemblies 24 and 26 are pulled axially out-
25 wardly in order to disassemble the suspension pivot.
In operation, the wheel supporting axle 12 of thesuspension of Figure 1 will traverse a jounce and rebound path
as the vehicle's wheels move over irregularities in the road.
At the same time, the spring 14 will flex and the eye 16 of
30 the spring will pivot about the axis extending through the
ball studs 47 and 64. The polyethylene bearing cups 28 and
60 permit low friction movement between the pivot parts. The
seals assure that the bearings 28 and 60 retain lubrication
and the pivot parts do not become contaminated which could lead
35 to premature wear.
The foregoing description presents the presently
preferred embodiment of this invention. Details of construc-
tion have been shown and described for purposes of illustration
rather than limitation. Modifications and alteration of the
40 invention may occur to those skilled in the art that will come
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within the scope and spirit of the following claims.
